Contec bx200 SERIES, Руководство пользователя

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6. Appendix
100
BX-2x0-DCxxxx, BX-2x0D-DCxxxx User’s manual
(1) Example flow chart
WDT
Restart?
END
START
No
WDT Stop
WDT Initial
WDT Start
Yes
If [WDT Stop] is not performed within the limit time set up
by [WDT Start], system reset occurs.
}
When performing the re-start of WDT, it repeats [WDT Start] and [WDT Stop].
* It is also possible not to perform [WDT Stop] instead of performing [WDT Stop] to [WDT Start], but to perform [WDT
Start] continuously at the time of a re-start.
(2) Example programming
The following example is written in Intel8086 assembly language.
In this example, open and close commands are written separately for the sake of convenience, but in an
actual program, always ensure that open is executed before a command is issued and that close is always
executed when a command is issued.
;===============
; WDT Open
;===============
CHK_OPEN1:
MOV
DX,2A4H
IN AL,DX
TEST AL,2 ;Check status of output
JNZ CHK_OPEN1
MOV DX,2A0H
MOV AL,87H ;Open Command
OUT DX,AL
CHK_OPEN2:
MOV
DX,2A4H
IN AL,DX
TEST AL,2 ;Check status of output
JNZ CHK_OPEN2
MOV DX,2A0H
MOV AL,87H ;Open Command
OUT DX,AL
CHK_OPEN3: ;Check status of input
MOV DX,2A4H
IN AL,DX
TEST AL,1
JZ CHK_OPEN3
MOV DX,2A0H
IN AL,DX ;Open success if AL = AAH